1. Field of the Invention
The present invention relates to a novel compound having an inhibitory activity against at least one of neutral ceramidase and alkaline ceramidase, a method for producing the novel compound, use of the novel compound, and a novel microorganism that produces the novel compound.
2. Description of the Related Art
Atopic dermatitis is an intractable chronic eczema accompanied by intense itching and involving repeated aggravation and amelioration, and is thought to be caused in allergic constitution by various irritants derived from the environment.
The skin has a barrier function of preventing bacterial infection and water evaporation from bodies. This barrier function is degraded in atopic dermatitis. Then, bacterial infection, allergen invasion, etc. occur under extremely dry conditions, so that the symptom is further aggravated repeatedly. One known cause of the aggravation is neutral/alkaline ceramidase produced by Pseudomonas aeruginosa (see, for example, Okino et al. J. Biol. Chem. 273, 14368-14373, 1998; and Okino et al. J. Biol. Chem. 274, 36616-36622, 1999). That is, in one possible specific process through which atopic dermatitis is aggravated, ceramide of the skin of a patient with atopic dermatitis, who is infected with Pseudomonas aeruginosa in many cases, is decomposed and decreased by neutral/alkaline ceramidase produced by Pseudomonas aeruginosa, so that the barrier function of the skin is degraded.
Thus, a compound that inhibits ceramidase produced by Pseudomonas aeruginosa is expected to prevent a decrease of ceramide and hence prevent aggravation of atopic dermatitis. However, at present, there is no critically useful therapeutic method for atopic dermatitis, although the skin has been maintained clean and/or a steroid drug, a humectant, etc. have been applied for treating atopic dermatitis. Thus, demand has arisen for developments of a new compound having an excellent inhibitory activity against neutral/alkaline ceramidase and a more effective, safe novel therapeutic drug for atopic dermatitis.